scholarly journals MODIFIED POLYLACTIDE FILAMENTS FOR 3D PRINTING WITH IMPROVED MECHANICAL PROPERTIES

2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Janez Slapnik ◽  
Rajko Bobovnik ◽  
Maja Mešl ◽  
Silvester Bolka
Keyword(s):  
Thermal Properties ◽  
3D Printing ◽  
Impact Strength ◽  
Charpy Impact ◽  
Charpy Impact Test ◽  
Core Shell ◽  
Mechanical And Thermal Properties ◽  
3D Printed ◽  
Injection Molded ◽  
Charpy Impact Strength

We investigated the effects of two different types of impact modifiers, i.e. core-shell rubber and aliphatic polyester, on the mechanical and thermal properties of polylactide (PLA) filaments for 3D printing. First, PLA/impact modifier blends with various concentrations of impact modifiers were prepared by melt blending in a co-rotating twin screw extruder and test specimens by injection molding. The mechanical and thermal properties of blends were investigated by tensile and bending tests, dynamic mechanical analysis (DMA) and Charpy impact test. It was found that core-shell rubber remarkably improved Charpy impact strength at loadings above 5 wt % (up to 746 %). As shown by DMA, the PLA/10 wt % core-shell rubber blend exhibited better damping performance as compared to neat PLA over the whole examined frequency range, especially at high frequencies, which explained the increase in impact strength. The filament for a fused deposition modeling (FDM), 3D printer was prepared from blend with the highest impact strength (PLA/10 wt % core-shell rubber), whereas PLA and acrylonitrile-butadiene-styrene copolymer (ABS) filaments were used for reference. Test specimens were prepared by using a consumer FDM 3D printer. The mechanical and thermal properties were investigated by tensile and bending tests, DMA, Charpy impact test, and ultra-fast differential scanning calorimetry (Flash DSC). Specimens from PLA blend exhibited 109 % increase in Charpy impact strength as compared to neat PLA. In contrast to injection molded specimens, 3D printed PLA blend exhibited higher tensile E modulus than neat PLA, which was ascribed to improved interlayer adhesion. Moreover, DMA and Flash DSC analysis of 3D printed specimens showed an increase in the glass transition temperature as compared to injection molded specimens. This phenomenon was ascribed to reduction of free volume because of slow cooling in 3D printing process, which is also the reason for increased tensile E modulus of the PLA blend. All tested PLA, PLA blend and ABS filaments were in amorphous state as shown by Flash DSC analysis. Bending test showed an increased toughness of PLA blend in comparison to neat PLA and also higher toughness as compared to ABS. The modified polylactide (PLA/10 wt % core-shell rubber) filament thus combines easy processability of PLA filament and impact toughness of ABS filament.

Effects of Processing Parameters and Nanofillers on Mechanical and Thermal Properties and Morphology of Impact Modified Poly (lactic acid)

2013 ◽  
Vol 1499 ◽  
Author(s):  
Eda Acik ◽  
Ulku Yilmazer
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Impact Strength ◽  
Random Copolymer ◽  
Processing Parameters ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Injection Molded ◽  
The Impact

ABSTRACTTernary nanocomposites of poly (lactic acid) (PLA) were produced by melt blending with two types of elastomers and five types of organoclays to obtain improved mechanical properties such as tensile strength, modulus and impact strength. One of the elastomers is a random copolymer of ethylene and glycidyl methacrylate (E-GMA) and the other one is a random terpolymer of ethylene-butyl acrylate-maleic anhydride (E-BA-MAH). Organically modified montmorillonites (OMMT) were utilized as nanofillers. XRD, DSC, tensile and impact tests were done on the injection molded samples. FTIR, SEM and TEM analyses are still in progress. As preliminary results, thermal analysis showed that the addition of compatibilizers and organoclays does not have a distinct effect on the thermal properties of the composites, and no evidence of nucleation activity of compatibilizers or organoclays was found. For all types of organoclays, the nanocomposites produced with E-GMA exhibited better mechanical properties in comparison to nanocomposites containing E-BA-MAH, especially for the impact strength.

The influence of adding long basalt fiber on the mechanical and thermal properties of composites based on poly(oxymethylene)

2018 ◽  
Vol 33 (4) ◽  
pp. 435-450 ◽  
Author(s):  
Patrycja Bazan ◽  
Stanisław Kuciel ◽  
Mariola Sądej
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Average Length ◽  
Flexural Modulus ◽  
Basalt Fiber ◽  
Charpy Impact ◽  
Mechanical And Thermal Properties ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Atr Spectroscopy

The work has evaluated the possibility of the potential reinforcing of poly(oxymethylene) (POM) by basalt fibers (BFs) and influence of BFs addition on thermal properties. Two types of composites were produced by injection molding. There were 20 and 40 wt% long BFs content with an average length of 1 mm. The samples were made without using a compatibilizer. In the experimental part, the basic mechanical properties (tensile strength, modulus of elasticity, strain at break, flexural modulus, flexural strength, and deflection at 3.5% strain) of composites based on POM were determined. Tensile properties were also evaluated at three temperatures −20°C, 20°C, and 80°C. The density and Charpy impact of the produced composites were also examined. The influence of water absorption on mechanical properties was investigated. Thermal properties were conducted by the differential scanning calorimetry, thermal gravimetric analysis, and fourier transform infrared (FTIR)-attenuation total reflection (ATR) spectroscopy analysis. In order to make reference to the effects of reinforcement and determine the structure characteristics, scanning electron microscopy images were taken. The addition of 20 and 40 wt% by weight of fibers increases the strength and the stiffness of such composites by more than 30–70% in the range scale of temperature. Manufactured composites show higher thermal and dimensional stability in relation to neat POM.

Mechanical Properties of 3D-Printed Wood-Plastic Composites

2018 ◽  
Vol 777 ◽  
pp. 499-507 ◽  
Author(s):  
Ossi Martikka ◽  
Timo Kärki ◽  
Qing Ling Wu
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
3D Printing ◽  
Impact Strength ◽  
Polylactic Acid ◽  
Wood Plastic Composite ◽  
Wood Plastic Composites ◽  
Plastic Composite ◽  
Plastic Composites ◽  
3D Printed

3D printing has rapidly become popular in both industry and private use. Especially fused deposition modeling has increased its popularity due to its relatively low cost. The purpose of this study is to increase knowledge in the mechanical properties of parts made of wood-plastic composite materials by using 3D printing. The tensile properties and impact strength of two 3D-printed commercial wood-plastic composite materials are studied and compared to those made of pure polylactic acid. Relative to weight –mechanical properties and the effect of the amount of fill on the properties are also determined. The results indicate that parts made of wood-plastic composites have notably lower tensile strength and impact strength that those made of pure polylactic acid. The mechanical properties can be considered sufficient for low-stress applications, such as visualization of prototypes and models or decorative items.

scholarly journals Improving Mechanical Properties of PLA/Starch Blends Using Masterbatch Containing Vegetable Oil Based Active Ingredients

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2981
Author(s):  
Bianka Nagy ◽  
Norbert Miskolczi ◽  
Zoltán Eller
Keyword(s):  
Impact Strength ◽  
Vegetable Oil ◽  
Rapeseed Oil ◽  
Flexural Modulus ◽  
Charpy Impact ◽  
Sem Images ◽  
Elongation At Break ◽  
Starch Concentration ◽  
Starch Blends ◽  
Charpy Impact Strength

The aim of this research was to increase the compatibility between PLA and starch with vegetable oil-based additives. Based on tensile results, it can be stated, that Charpy impact strength could be improved for 70/30 and 60/40 blends in both unconditioned and conditioned cases, regardless of vegetable oil, while no advantageous change in impact strength was obtained with PLA-g-MA. Considering sample with the highest starch concentration (50%), the flexural modulus was improved by using sunflower oil-based additive, Charpy impact strength and elongation at break was increased using rapeseed oil-based additive in both conditioned and unconditioned cases. SEM images confirmed the improvement of compatibility between components.

scholarly journals 3D-Printable PP/SEBS Thermoplastic Elastomeric Blends: Preparation and Properties

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 347 ◽  
Author(s):  
Shib Banerjee ◽  
Stephen Burbine ◽  
Nischay Kodihalli Shivaprakash ◽  
Joey Mead
Keyword(s):  
3D Printing ◽  
Carbon Black ◽  
Computer Aided Design ◽  
Fused Deposition Modeling ◽  
Mechanical Performance ◽  
Polymeric Materials ◽  
Fused Deposition ◽  
3D Printed ◽  
Injection Molded ◽  
Preferential Location

Currently, material extrusion 3D printing (ME3DP) based on fused deposition modeling (FDM) is considered a highly adaptable and efficient additive manufacturing technique to develop components with complex geometries using computer-aided design. While the 3D printing process for a number of thermoplastic materials using FDM technology has been well demonstrated, there still exists a significant challenge to develop new polymeric materials compatible with ME3DP. The present work reports the development of ME3DP compatible thermoplastic elastomeric (TPE) materials from polypropylene (PP) and styrene-(ethylene-butylene)-styrene (SEBS) block copolymers using a straightforward blending approach, which enables the creation of tailorable materials. Properties of the 3D printed TPEs were compared with traditional injection molded samples. The tensile strength and Young’s modulus of the 3D printed sample were lower than the injection molded samples. However, no significant differences could be found in the melt rheological properties at higher frequency ranges or in the dynamic mechanical behavior. The phase morphologies of the 3D printed and injection molded TPEs were correlated with their respective properties. Reinforcing carbon black was used to increase the mechanical performance of the 3D printed TPE, and the balancing of thermoplastic elastomeric and mechanical properties were achieved at a lower carbon black loading. The preferential location of carbon black in the blend phases was theoretically predicted from wetting parameters. This study was made in order to get an insight to the relationship between morphology and properties of the ME3DP compatible PP/SEBS blends.

scholarly journals Effect of Selected Commercial Plasticizers on Mechanical, Thermal, and Morphological Properties of Poly(3-hydroxybutyrate)/Poly(lactic acid)/Plasticizer Biodegradable Blends for Three-Dimensional (3D) Print

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1893 ◽  
Author(s):  
Přemysl Menčík ◽  
Radek Přikryl ◽  
Ivana Stehnová ◽  
Veronika Melčová ◽  
Soňa Kontárová ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Three Dimensional ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Modulated Differential Scanning Calorimetry ◽  
3D Print ◽  
3D Printed ◽  
Biodegradable Blends

This paper explores the influence of selected commercial plasticizers structure, which are based on esters of citric acid, on mechanical and thermal properties of Poly(3-hydroxybutyrate)/Poly(lactic acid)/Plasticizer biodegradable blends. These plasticizers were first tested with respect to their miscibility with Poly(3-hydroxybutyrate)/Poly(lactic acid) (PHB/PLA) blends using a kneading machine. PHB/PLA/plasticizer blends in the weight ratio (wt %) of 60/25/15 were then prepared by single screw and corotating meshing twin screw extruders in the form of filament for further three-dimensional (3D) printing. Mechanical, thermal properties, and shape stability (warping effect) of 3D printed products can be improved just by the addition of appropriate plasticizer to polymeric blend. The goal was to create new types of eco-friendly PHB/PLA/plasticizers blends and to highly improve the poor mechanical properties of neat PHB/PLA blends (with majority of PHB) by adding appropriate plasticizer. Mechanical properties of plasticized blends were then determined by the tensile test of 3D printed test samples (dogbones), as well as filaments. Measured elongation at break rapidly enhanced from 21% for neat non-plasticized PHB/PLA blends (reference) to 328% for best plasticized blends in the form of filament, and from 5% (reference) to 187% for plasticized blends in the form of printed dogbones. The plasticizing effect on blends was confirmed by Modulated Differential Scanning Calorimetry. The study of morphology was performed by the Scanning Electron Microscopy. Significant problem of plasticized blends used to be also plasticizer migration, therefore the diffusion of plasticizers from the blends after 15 days of exposition to 110 °C in the drying oven was investigated as their measured weight loss. Almost all of the used plasticizers showed meaningful positive softening effects, but the diffusion of plasticizers at 110 °C exposition was quite extensive. The determination of the degree of disintegration of selected plasticized blend when exposed to a laboratory-scale composting environment was executed to roughly check the “biodegradability”.

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